Production of flavor-enhanced apple and prune concentrates



March 2l, 1967 E. M. BYER ETAL.

PRODUCTION OF FLAVOR-ENHANCED APPLE AND PRUNE CONCENTRATES Filed Jan,15, 1964 NA G GES $.25 mnzmnzou ).rFmSS NNH E N/f OQ \w: Y A NMC; l O LSO @lz T5 1% J w AAVM mb NQ VM d@ @NH /H ..N. D mmzm ou mw mwzmuzou 5 EOlmom 1 l R QLMVH L F OE GHM o5 lov N lN 3 L L D N EA IW h x \v\\n\\ 4,om Y www @mv N mmAoou Q WN .maw QE mmv .www 5 wzm ou wszo .w .......M.Mb .h QN U mw U un. UAE U Q U 9 SE Q. mi n m u2` 23mm muNEw, QON. O-. YL s i m5 Qom uur m om m n Av w m m a Nw m l QE n H I, n d A. J Ow d n ng D \l iwhwmfm .5.1 QUIN n MOH OH United States Patent O 3,310,409PRODUCTHON F FLAVOR-ENHANCED APPLE AND PRUNE CONCENTRATES Ellis M. Byer,Albany, Oreg., and Alfred A. Lang, Winter Haven, Fla., assignors ofone-third to General Foods Corporation, White Plains, N.Y., acorporation of Delaware Filed Jan. 13, 1964, Ser. No. 342,843 Theportion of the term of the patent subsequent to Jan. 21, w81, has beendisclaimed 8 Claims. (Cl. 99--205) This application is acontinuation-in-part of our application Ser. No. 244,235, filed Dec. 3,1962, now U.S. Patent No. 3,118,775, for Production of Flavor-EnhancedGrape and Tomato Concentrates which application was a division of ourapplication Ser. No. 859,885, filed Dec. 16, 1959, under the title ofProduction of Flavor-Enhanced Vegetable Concentrates which isabancloned.

The present invention relates to the production of flavor-enhanced juiceconcentrates and, more particularly, to a process for the recovery fromthese juices of volatile constituents useful for such enhancement.

It is an object of the present invention to provide a process whereby avolatile flavor fraction can be recovered from fruit juices in a simpleand practical manner whereby concentrates of these juices can befortified with a fresh fruit-like flavor which they otherwise would notoffer.

A specific object of the invention is to provide means whereby a highyield of a desired fruit flavor fraction can be recovered simply withoutemploying sophisticated plant equipment.

A still further object of the invention is the recovery of avorfulessences from fruit juices in a condition whereby such essences can berestored to a juice concentrate and will offer to the reconstitutedjuice fresh fruit flavors even after prolonged storage.

Heretofore, it has been proposed to flavor-enhance juice concentrates byrecovering most of the volatile flavor-producing constituents evaporatedin the course of concentrating fruit juices, These constituents havevarious high and low boiling points. Thus, the art has been concerned inthe past with the problems encountered in collection of all or most ofthese constituents. Suggested procedures have called for condensation,absorption, or other means for separation and collection of volatileessences, including esters, alcohols, aldehydes and other organicconstituents calling for employment of a wide range of temperatures andpressures. Hence, it has been proposed to collect the volatile essencesproduced in the course of partial evaporation of a juice by means ofmulti-stage condensers at progressively reduced temperatures; forexample, it has been proposed to employ a first-stage condensation above32 F., a secondstage condensation below 32 F. in the neighborhood of acold brine solution, and a third-stage condensation in neighborhoodsless than 130 F. Clearly, such collection techniques are wasteful ofexpensive refrigerants such as liquid nitrogen, liquid air, and thelike, and require complex condensate handling means which limit theapplicability of such procedures on a wide scale in the juiceconcentration art. Moreover, such a collection techniques involve therecovery of a large quantity of low molecular weight gases such asnitrogen, carbon dioxide, oxygen and other non-condensables which have ahigh diffusivity, create a high velocity and hinder the ability tocondense the desired volatile essences on a practical scale.

Others in the art have suggested procedures whereby flavor valuesproduced in the course of a partial evap- 3,319,409 Patented Mar. 21,1967 ICC oration of a juice are condensed at less reduced temperatures;here also, however, the prior art workers have mainly been concernedwith the collection of as much as possible of these volatileconstituents, including the more volatile materials and, as aconsequence, have suggested the use of relatively complex packedfractionating columns, singly or in series. Such means generally place asubstantial burden upon plant investment and operation and have not beenfound to produce an adequate yield or quality of tiavoring material foruse in fortification of concentrates. In the main, such techniques havebeen concerned with the recovery of constituents which boil attemperatures lower than the boiling point of water and hence have notinvolved the recovery as well of constituents which boil at temperatureshigher than the boiling point of water. Although low boilingconstituents offer some fragrance reminiscent of fresh juice, they arerecovered at only a minor relatively inconsequential level such thattheir use in large quantities on a commercial basis is impractical.

The present invention provides a procedure whereby a high yield ofuseful volatile flavoring constituents can be recovered in a practicalconcentration for subsequent use in a manner which satisfies theaforementioned objects. Advantageously and unexpectedly this specificflavor fraction is recovered under only moderately reduced workingtemperatures and, surprisingly, is isolated from volatile fractionsheretofore considered commercially useless and, hence, discarded. Theprocedure of the present invention is not complicated, therefore, by theuse of drastically reduced condensation temperatures, can be combinedwith existing plant installations at a relatively small additionalcapital investment, and in use does not place an undue burden on plantproduction requirements.

The present invention is applicable to a variety of fruit juices whichrange in their sensitivities to operating ternperatures. The term fruitas it is employed herein and in the accompanying claims is intended toapply to noncitrus fruit juices typified by those from tomato,strawberries, boysenberries, grape, prune, apple, and the like.

The present invention recovers the aforesaid specific fraction ofvolatile constituents from fruit juices by a series of steps, whichcomprise:

(a) causing the fruit juices to fiow rapidly, preferably in a thin,continuous film, over a heat exchange surface which is under asubstantially reduced subatmospheric pressure typically less than 11/2of mercury, in a closed system to partially concentrate the juice byseparating it into a major juice concentrate portion and minor volatileportion condensed to include flavor-producing volatile constituentsboiling at temperatures higher and lower than that of water and toexclude non-condensa'ole gaseous constituents. The temperatures employedto effect such separation will be dependent in great measure upon theidentity of the juice being processed. For juices typified by tomato,temperatures may be employed, of say F., where the flavors in the juiceconcentrate portion as well as desired constituents separated therefromare not relatively sensitive to heat;

(b) the yaforesaid volatile fraction produced by the first step isthereafter subjected Vto condensation continuously, at such temperaturesthat the volatile flavor-producing constituents are collected as atwo-phase oilywatery mixture. Advantageously, the temperatures at whichthis oily-watery mixture may be collected by condensation may be onlymoderately reduced, typically 30-70 F. Usually, it is found that thedesired condensate collected is in the neighborhood of 5.-15% by weightof the juice initially introduced to the heat exchange surface;

(c) the aforesaid two-phase mixture is thereafter separated into a minorsubfraction containing desirable high as well as low boilingflavor-producing constituents and a major subf'raction containing mainlypreviously condensed water and an undesirable quantity of oilyflavorproducing constituents. It is this minor subfraction which hasbeen found offers the desirable avor enhancement to the juiceconcentrate. Such separation can be carried out by azeotropicdistillation of the two-phase mixture under absolute pressures of lessthan 11/2 of mercury at temperatures of 50-100 F. or by any otherprocess yielding substantially the same minor subfraction, as will bedescribed hereinafter. The desirable subfraction which is collectedcomprises `as a major proportion a watery phase and as a minorproportion an oily phase. This minor subfraction may be collected bycondensation at temperatures of 30-70 F. as will be describedhereinafter. Preferably the minor subfraction is further subdivided byallowing the watery and oily phases to separate one from another uponstanding, the watery phase being continuously removed from the bottom ofthis separation while accumulating an oil level on the surface; uponsufficient oil accumulation, this oil is drained off separately andsubsequently mixed with a quantity of suitable high boiling organicmaterial. For the purposes of the present invention it is preferred thatthis minor subfraction be collected by condensation in a closed system,that is one where no external vapors are introduced to the minorsubfraction.

The minor subfraction of use generally represents about 0.5-1.5 byweight of the whole juice. The specific subfraction of use is ideallyrecoverable by evaporation at only moderately elevated temperatures andby condensation at temperatures ranging above 30 F. and upwardly to 70F. when employing absolute pressures in the neighborhood of less than1/2 in. of Hg; however, this t fraction may -also be condensed attemperatures below 30 F. by means of a brine solution or otherrefrigerating means which, depending on the temperature of condensation,may cause icing in the collection vessel and which permit recovery ofthe fraction as a snow rather than liquid.

It will be recalled that the foregoing process for recovering thevolatile fruit flavor fraction desired may be carried out undersubatmospheric pressures at only moderately elevated temperatures in theinitial whole juice concentration step; the juice concentrate portionmay be subsequently introduced on either a continuous or batch basis tofurther heat exchange equipment wherein it may be caused to again travelin the form of a thin film over one or more heat exchange surfaces alsomaintained under subatmospheric pressures but at higher temperatureswhereby the more concentrated juices will be reduced in viscosity andthereby more effectively concentrated. Thus, evaporation temperaturesabove 100 F. m-ay be practiced in the case of fruit juices like grape ortomato. It has been found useful in the present process to employ highlyvolatile so-called refrigerant gases, typically ammonia, which whencompressed contain sufficient latent as well as sensible heat to boilthe desired volatile constituents. Since the desired flavor fraction iscollectable by condensation at temperatures above 30 F., a continuousheat exchange cycle employing such refrigerant gases is ideally suitedto the present process; thus, after the compressed refrigerant gas hassurrendered its heat to the juice or juice concentrate, it can beemployed in its liquid state to remove sensible heat as well as the heatof condensation from the distilled fraction, the heat of which can bereused to heat the liquid refrigerant for subsequent cycles. The heat ofa compressed refrigerant gas may be utilized directly to boil furtherquantities of juice or it may be employed indirectly through transfer toanother medium such as water which could serve in boiling the juice orthe concentrate. However, it is not intended that the present process berestricted to the use of such refrigerant gases since steam may beintroduced to the heat exchange surface to effect juice concentration aswell as redistillation of the two-phase oily watery mixture and sincecold water can be employed to condense the minor volatile portionseparated from the initial concentration step as well as the redistilledvolatile fraction.

It is preferred that the non-condensables not be collected so that theredistilled condensate employed for fiavor enhancement is relativelyfree of those materials like carbon dioxide and oxygen which impair theflavor values of the concentrate even at temperatures below 0 C. It ispreferred that the non-condensables and the difiicultly condensablevolatile vapors be evacuated from the initial concentration of the juicein a non-oxidizing atmosphere and discarded, thereby freeing the firsttwophase oily-water mixture collected of interference from suchnon-condensables and highly Volatile constituents stemming from theirhigh gas velocities and resulting in more stable juice concentratesfortified with the specific` fiavor fraction of the present invention.In this connection it is noteworthy that the juice concentratesfortified with this flavor fraction have been characterized by theirimproved freedom from oxidative changes and the accompanying ability toavoid use of costly nitrogen packaging.

Ideally, the specific flavor fraction of use may be mixed in liquid formwith the juice concentrate thereby offering the advantages of a simpleplant recirculation. However, it has been found that a rather prolongedshelf-life for flavor-enhanced concentrate is achieved when the specificflavor fraction of use is frozen into individual portions or pieces,typically cubes or discs, which are introduced to the juice concentratein the can or other package just prior to freezing. It appears that, bymaintaining the specific avor fraction in a frozen condition separatefrom the frozen concentrate, the flavor values of the product aremaintained over an unusually long period of time.

The invention will now be more fully described by reference to theaccompanying drawing. The drawing is a schematic view of a typical plantoperation for carrying out juice concentration and iavor enhancement inaccordance with this invention.

Referring to the drawing, the system will be seen to comprise a tripleeffect evaporator into which a compressed refrigerant gas is introducedto supply heat for boiling the apple or prune juice indirectly throughrecirculated water. However, the present invention is not to berestricted to the modification of juice concentrator to be describedherein since apparatus capable of employing a hot compressed refrigerantgas in a direct heat exchange relationship with boiling juices may alsobe employed, typically the system disclosed in U.S. Patent No. 2,570,-210 to Joseph A. Cross issued Oct. 9, 1951.

For the preferred apple or prune juice concentrator of the presentinvention, a series of connected falling film type evaporator units 10A,10B and 10C are employed, each unit comprising a vertical tubularevaporator having a shell and a nest of tubes (not shown) which areretained by suitable upper and lower tube sheets (not shown) in theshell, In the first effect evaporator 10A water is recirculated througha hot refrigerant gas condenser 20 of the shell and tube-type where theheat of the hot gas is transferred through the walls of the tubes, waterheated thereby being brought into heat exchange relationship with thetubes of evaporator unit 10A by means of hot water line 2.1. After thewater in the first effect evaporator unit 10A has been brought into heatexchange relationship with the tubes therein to elevate the juicetemperature and volatilize low and high boiling aromatic constituentstherein, the water is withdrawn from the top of the evaporator throughpipe 22, water being recirculated to condenser 20 by means of pump 23and pipe Z4. A suitable ammonia compressor 25 communicating with ammoniacondenser 20 through ammonia gas line 28 compresses ammonia vaporwhereby hot ammonia gas is delivered int-o heat exchange relation withgas condenser 20, condensed liquid ammonia collected in condenser 20fiowing into ammonia receiver 27 through line 29. Liquid ammonia inreceiver 27 is floated on am- Inonia line 27A to maintain an adequatesupply of liquid ammonia for level control means 27B of vapor condenser82.

Fresh juice is supplied to evaporator unit C through -a suitable feedpipe 40. Feed pipe 40 preferably is located to feed fresh juice justbelow the level of liquid in sump 70C. A fiow control valve 12C beinglocated in pipe 4t) controlling the rate at which fresh juice isdelivered to sump 70C and being operated under the control of pneumaticlevel control means 13C in communication with tail pipe 14C for sump70C. Fresh juice entering the sump 70C is delivered by tail pipe 14C tocirculator pump 42C which delivers a portion of fresh dilute juicethrough pipe 44C t-o the upper extremity of evaporator unit 10C andanother portion of fresh juice through pipe 46B for evaporation in thesecond effect evaporator unit 10B, a majority 4of the juice beingdelivered to the third effect evaporator unit 10C. Fresh juice enteringthe third effect concentrator 10C flows downwardly within each of thetubes therein (not shown), the juice being distributed in the tubes bymeans of a header having suitably mounted therein distributor tubes, adistributor tube being mounted at the upper extremity of each heatexchange tube for assuring uniform distribution of juice in the form ofa falling film in positive contact with the inner walls of the tube, allof which is well known to those skilled in the art, e.g. FIG. 4 oftheaforesaid Cross patent.

In the system diagrammed in the drawing, the boiling juice vapors of thefirst evaporator unit 10A are brought into heat exchange relationthr-ough duct 60 with juice being circulated to the nest of heatexchange tubes in second effect evaporator 10B, and the boiling juicevapors in the second effect evaporator are delivered through duct I62into heat exchange relationship with the nest of tubes for the thirdeffect evaporator. Thus boiling juice vapors introduced to the shellsurround the nest of heat exchange tubes therein and transfer their heatof liquefaction to juice traveling downwardly in contact with the innerwalls of the heat exchange tubes in unit 10C, the concentrated ,juicebeing -collected at sump 70C in the lower extremity of evaporator 10Cwith the vap-ors introduced to the shell of evaporator unit 10C beingcondensed therein, collected and removed from the area around the baseof the heat exchange tubes through pipe 72 and delivered by vaporcondensate pump 74 through tline 75 to an ammonia subcooler generallyshown at 76. Similarly, concentrated juice from the first effectevaporated 10A is collected in sump 70A. The juice vapors condensed inthe second effect evaporator 19B are removed through pipe 72B anddelivered through U-shaped vapor condensate trap 78 and pipe 80communicating with draw-off pipe 72C through the intermediation of the.pool for vapor condensate around the lower extremities of the nest ofheat exchange tubes in the third effect evaporator.

In operation fresh juice is admitted through control valve 12C in pipe40 to maintain a fixed level of juice in sump 70C of the third effectevaporator unit; similarly, valve 12B is adjusted to effect a llevel ofjuice in the sump '70B of the second effect evaporator and valve 12A inline 46A maintains a suitable level of juice in sump 70A of the firsteffect evaporator, pneumatic level control means 13A, B and C,respectively, being employed to control the operation of valve means12A, B and C, sensing devices for the pneumatic liquid control unitsbeing in communication with tail pipes 14A, B and C, respectively, theoperation -of such means being well known to those skilled in the art,Thus, through the operation of the valve means just described the rateat which fresh dilute juice and portions of concentrated juice aresupplied to the individual evaporator units is controlled to provide asubstantially uniform level of juice in the respective sumps of thevarious effects.

A vacuum i-s drawn through lines 90B, 90C and 90D communicating withevaporator units 10B and 10C and vapor condenser 82, respectively, Thelines 90B, C and D serve to remove difficultly condensable volatilefiavor constituents and non-condensable gases boiling over with juicevapors. The suction drawn through lines 90B, C and D is effected by anywell known steam ejection system, the design of which is well known tothose skilled in the art, a three stage steam ejection system with ah-ogging jet being generally shown at 92.

Hence, in operation fresh dilute juice delivered to the system throughpipe 4t) will be evaporated and concentrated through the successivestages of evaporator units 10C, 10B and 10A and eventually delivered bycirculation pump 42A through product pipe 48A to additional evaporatorsfor further concentration and subsequent combination with other juiceconstituents for aromatizing the juice, as will be hereinafterdescribed; the boiling juice vapors produced in the third effectevaporator 10C are removed therefrom through vapor duct 64 and deliveredto a tube-type vapor condenser 82 in heat exchange relationship with thevapors, cold liquid ammonia circulating through the tubes of thecondenser 82 bringing about condensation of the vapors around the tubesin condenser 82,` wherefrom the vapors are collected at sump 84,delivered through pipe to pump 86 and pipe 33 which delivers the juicevapor condensate to means for further concen tration in accordance withthe present invention. The juice vapors condensed in the third effectevaporator 10C and removed through pipe 72C are circulated by pump 74through line 75 to an ammonia subcooler generally shown at 76. Liquidfrom ammonia receiver 27 reaches the subcooler 76 through line 27A,ammonia subcooler '75 serving to further cool liquid ammonia by havingthe relatively cooler waste condensate in line 75 brought into heatexchange Irelation with the liquid ammonia. Thus, the temperature ofammonia circulated through line 77 and level control means 27B to vaporcondenser 82 is lowered and the efficiency of the vapor condenser isincreased. In this connection the heat transferred from juice vapors inthe condenser 82 is transferred to the liquid ammonia, the latter beingrecirculated back to ammonia receiver 27 through suction line 27D toammonia receiver 26.

Thus, the Iliquid phase recovered by the condenser 82 is essentially thevapor condensate of fresh dilute juice and is substantially free of thedifiicultly condensable vapors and non-condensable gases such asnitrogen, carbon dioxide and oxygen. This liquid phase is recovered inthe course of initial concentration of `fresh juice by subjecting thejuice to reduced subatmospheric pressures generally less than 11/2A ofmercury absolute and ranging typically downward to about 1/2 of mercuryand below; as indicated previous-ly the fresh dilute juice is subjectedto such evaporation at temperatures which will not occasion degradationof the various desirable essences evaporated but generally will be at atemperature above about 70 F. and not exceed about 140 F., the range oftemperature sensitivities varying, of course, for various juices. Theliquid phase contains various constituents (predominately water) many ofwhich boil at temperatures higher as well as lower than that of water.In general, this liquid phase will be recovered as a minor proportion byweight of the fresh juice being subjected to evaporation in the thirdeffect.

This liquid phase is subjected in accordance with the present inventionto a redistillation to recover a desired oily-watery fraction. Thus, theliquid phase in pipe 88 is introduced to an evaporat-or unit wherein itis caused to travel in the form of a thin film along a preferablyelongated heat exchange surface which is in heat exchange relationshipwith a hot gas or fliquid, typically, hot ammonia gas. One form ofevaporator comprises a tube-type evaporator having a plurality ofvertically arranged elongated tubes suitably nested at their upper andlower eX- tremities and adapted to receive the .liquid phase deliveredthereto from pipe 8S. Preferably an evaporator of the type shown in theaforesaid Cross patent is employed, a suitable distributor pipe such asthat shown in FIG. 4 of Cross being located at the upper mouth of eachtube to cause the liquid phase to travel uniformly down along the insideheat exchange surface thereof. Hot ammonia gas from compressor 25 isdelivered through inlet pipe 114 communicating with shell 116surrounding the nest of tubes, hot ammonia gas being thereby placed inheat exchange relation with the liquid films forming within the tubesand thereby bringing about transfer of sensible heat and latent heat ofevaporation to the liquid phase; hot ammonia gas condensing around thetubes is contained within and removed from the shell as a liquid throughliquid ammonia pipe 118 communicating with ammonia receiver 27.Substantially all of the low boiling constituents (relative to theboiling point of water) together with certain high boiling constituentsare volatilized in the tubes and conducted through duct 120 to vaporcondenser 126 wherein they arecondensed, The balance of the liquid phasein the tubes which has not volatilized contains high boilingconstituents which are undesirable and these materials are collected ina suitable sump generally shown as 122 and pumped as at 124 to asuitable waste. Generally the waste from the liquid phase will be amajority by weight of the liquid phase being treated in the evaporator,typically, 85-95 parts by Weight of the liquid phase. Condenser 126 isof the tube-type and has the vapors condensed therein by means of liquidammonia in the neighborhood of 30 F.; the vapors condensed around thetubes of the condenser 126 are collected as an only-watery fraction andare removed therefrom by means of pump 130 communicating with condensershell 132 through pipe 134. An ammonia gas line 138 connects the shellof condenser 126 with the shell of the surge drum of level control means27B wherefrom gas is recirculated through line 27D to compressor 25. Avacuum line 140 connects the shell of condenser 126 with vapor condenserS2 from which it derives its vacuum, the latter being under negativepressure from the lvacuum system generally indicated at 92. Thus, theliquid phase entering the redistillation unit is subjected to a reducedabsolute pressure generally between 11/2 and 1/2 of mercury and below.The temperature of the liquid phase entering the redistillation unitwill typically be about 60 F. and generally should be at a temperaturewhereat low and high boiling constituents are maintained in the liquidphase. The temperature of the liquid phase in the redistillation unitshould be above that temperature where, at the particular pressureemployed, approximately of the liquid phase will be volatilized andrecovered as an oily-watery condensate fraction in condenser 126; theyield of oily-watery fraction condensate will be dependent upon a numberof variables including the total area of the heat exchange surface towhich the liquid phase may be exposed, the temperature on said surface,the absolute pressure existing in the redistillation unit and theduration of exposure of the liquid phase to any particular temperature.Any volatile constituents vaporized in the course of redistillation andnot collected by condenser 126 will be circulated through vacuum pipe140 to vapor condenser 82 whereby such vapors may be condensed andrecycled or in the case of highly volatile or non-condensableconstituents removed through vacuum line 92.

As indicated previously the discovery that the high as well as lowboiling components of this oily-watery fraction are useful in enhancinga juice concentrate with a well rounded and complete flavor and aromawas to some extent unexpected since it had been previously believed thatonly the low boiling constituents were useful in this capacity and sincethe higher boiling constituents had been generally classed as a groupmaking no desirable contribution to flavor and aro-ma and, indeed,detracting from over-all acceptability. The oily-watery fraction may beadded back directly to the concentrate or to fresh dilute juice to which-concentrate has theretofore been added, to give the concentrates anatural flavor. However, it is an advantage of the present oily-wateryfraction that fresh dilute juice need not be employed in preparingsuitably flavored nished concentrates and, indeed, it is a preferredpractice not to employ fresh dilute juice but to add the oily-wateryfraction to juice concentrate. Collateral to this advantage, therefore,is the practicality of concentrating the juice to a lower density thanthat to which juice concentrate is normally reduced, the practice ofadding fresh dilute juice is no longer necessary. It is believed bylsome workers in the prior art that the presence of oxygen and carbondioxide and possibly other unknowns in the tornato or grape juiceconcentrate is detrimental to iiavor stability. By virtue of theelimination of most if not all of these constituents in the course ofconcentration of the juice and by the avoidance of the need for freshdilute juices which contain many of these undesirables such as oxygenand carbon dioxide the avorful juice concentrate is found to be quitestable and the need for nitrogen sparging or other inert maintenance isreduced.

It will be noted from the foregoing description that the heat of thecompressed refrigerant gas is employed both (l) to boil the juice andseparate therefrom desired volatiles containing flavor-producingconstituents which boil at temperatures above and below that of water;and (2) to distill from the two phase oily-watery mixture recovered bycondensation a fraction containing said high and low boilingflavor-producing constituents. It will also be noted that when the hotcompressed refrigerant gas is brought into heat exchange relation withthe juice and the juice condensate it surrenders its heat and liquees,whereafter it is recycled to a receiver and evenvtually may be used tocondense either the volatiles recovered by boiling the juice or thedesired flavor fraction recovered upon condensation. Advantageously,therefore, the flavor fraction of use is recovered as part of a cyclewherein the refrigerant gas is also employed to concentrate the juice.By repeatedly recirculating the refrigerant the latent heat of therefrigerant in a compressed condition may be utilized to supply heat forevaporation and the liquefied refrigerant may be ernployed to receiveheat from vapors where a vapor condensate is to be recovered from thesystem. In practice a larger amount of oily-phase is recovered than isactually desired for use and a majority of that which is collected andused is of the watery-phase. As a consequence after a substantialportion of this oily-watery fraction is recovered that which is to beused will be separated from that which is not to be used such as bypermitting the emulsion to settle in an elongated chamber and therebyseparate into its respective phases which phases are then separated sothat at least a majority and preferably a large majority of the fractionused will contain the constituents of the watery-phase.

While the present invention has been described with particular referenceto specic examples, it is not to be limited thereby, but reference is tobe had to the appended claims for a definition of its scope.

What is claimed is:

1. Process of separating and recovering from a juice selected from thegroup consisting of apple and prune a specific fraction of volatileconstituents whose boiling points are below and above that of water,comprising separating the juice into a major concentrated juice portionand a minor volatile portion which contains said volatileflavor-producing -constituents and non-condensable gaseous constituentsby subjecting the juice to a high vacuum concentration operation at atemperature less than F., condensing a major proportion of the volatileflavor-producing constitutents as a first two-phase oily-watery mixtureand evacuating uncondensed volatile constituents and non-condensablegases as a minor proportion of the volatile portion, discarding saidminor proportion of the volatile portion, and thereafter distilling aflavorful and aromatic mixture of said high and low boiling constituentsfrom the resulting two-phase oilywatery mixture at a temperature of50-l00 F. and an absolute pressure of less than 11/2," of mercury bycausing a thin film of said two-phase oily-watery mixture to travelalong a heat exchange surface land condensing a minor subtraction ofsaid mixture, a major portion of said minor subtraction being awatery-phase and a minor portion of said subtraction being anoily-phase.

2. A process of fortifying a juice selected from the group consisting ofapple and prune with a specific fraction of volatile constituents whoseboiling points are above and below that of water, comprising separatingthe juice into a major concentrated juice portion and a minor volatilewhich contains said volatile davor-producing constituents andnon-condensable gaseous constituents by subjectin-g the juice to a highvacuum concentration operation at a temperature less than 140 F.,condensing a major proportion of the volatile davor-producingconstituents as a first two-phase oily-watery mixture and evacuatinguncondensed volatile constituents and noncondensable gases as a minorproportion of the volatile portion, discarding said minor proportion ofthe volatile portion, thereafter distilling a flavorful and aromaticmixture of said high and low boiling constituents from the resultingtwo-phase oily-watery mixture at a temperature of 50-100 F. and anabsolute pressure of less than 11/2 of mercury by causing a thin film ofsaid two-phase oily-watery mixture to travel along a heat exchangesurface and condensing a minor subtraction of said mixture, a majorportion of said minor subtraction being a watery phase and a minorportion of said minor subtraction being an oily-phase, and combiningsaid minor subtraction with juice concentrate.

3. A process ot tortifying a juice selected from the group consisting ofapple and prune with a specific fraction of volatile constituents whoseboiling points are above and. below that of water which comprisesbringing the juice to a temperature of 7D140 F. under an absolutepressure less than 11/2 of mercury in a closed system to partiallyconcentrate said juice by separating it into a major concentrated juiceportion and a minor volatile portion which contains said volatileavorproducing constituents and non-condensable gaseous constituents,subjecting said minor volatile portion to condensation at suchtemperatures that the major proportion of the volatile flavor-producingconstituents therein are collected as a first two-phase oily-waterymixture, evacuating uncondensed volatile constituents andnon-condensable gases as a minor proportion of said minor volatileportion, discarding said minor proportion of the volatile portion,distilling a flavorful and aromatic mixture of said high and low boilingconstituents from 4the resulting two-phase oily-watery mixture at atemperature approximating 100 F. and an 'absolute pressure less than11/2 of mercury by causing a thin film of said two-phase oily-waterymixture to travel along a heat exchange surface and condensing a minorsubtraction of said mixture, a major portion of said minor subtractionbeing a watery-phase and a minor portion of said minor subtraction beingan oily-phase, combining the wateryphase and a portion of theIoily-phase of said. condensed minor subtraction with previouslyconcentrated juice, and thereafter packaging and freezing said combinedjuice concentrate and the combined phases of said minor subtraction.

4. A process of fortifying a juice selected from the group consistingyof apple and prune with a specific fraction of volatile constituentswhose boiling points are above and below that of water, which comprisesbringing the juice to a temperature above about 70 F. and below about140 F. under an absolute pressure of less than 11/2" of mercury in aclosed system to partially concentrate said juice by separating it intoa major concentrated juice portion and a minor volatile portion whichcontains said volatile flavor-producing constituents and non-condensablegaseous constituents, subjecting said minor volatile portion tocondensation at such temperatures that the major proportion of thevolatile flavorproducing constituents therein are collected :as a firsttwo-phase oily-watery mixture, evacuating uncondensed volatileconstituents and non-condensable gases as a minor proportion of saidminor Vol-atile portion, discarding said minor portion of the volatileportion, distilling a flavorful and aromatic mixture of said high andlow boiling constituents from the resulting two-phase oily-waterymixture at a temperature approximating F. and an absolute pressure ofless than 11/2 of mercury by causing a thin tllm of said two-phaseoilywatery mixture to travel along a heat exchange surface andcondensing a minor subtraction of said mixture, a major portion of saidminor subtraction being a wateryphase and a minor portion of said minorsubtraction being an oily-phase, further concentrating said concentratedjuice portion, and combining the condensed minor subtraction with saidfurther concentrated juice portion.

5, A process according t-o claim 4, wherein the wateryphase and theoily-phase of said minor subtraction are separated, and thereaftercombining the watery-phase and 'a portion of the oily-phase of saidminor subtraction with said further concentrated juice portion.

6. A process according to claim 5 wherein a portion of whole juice isadded to the combination of juice concentrate and said minorsubtraction.

7. Continuous process for producing a davor-enhanced juice selected fromthe group consisting of apple and prune by concentrating a heatsensitive juice and separating and recovering therefrom a specificfraction of volatile constituents whose boiling points are above andbelow that of water, comprising utilizing the heat contained in acompressed refrigerant gas to boil the juice at relatively lowtemperatures of from 70-140 F. under vacuum to partially concentratesaid juice by separating it into a major concentrated juice portion anda minor volatile portion which contains volatile flavor-producingconstituents, water and non-condensable gaseous constituents, liquetyingand causing the refrigerant to cool to a temperature substantially belowthe temperature of said minor volatile portion, using the cool liquefiedrefrigerant to condense a major proportion of said minor volatileportion as a fresh two-phase oily-watery mixture, evacuating uncondensedvolatile constituents and noncondensable gases as a minor proportion ofsaid minor volatile portion, discarding said minor proportion of thevolatile portion, utilizing the heat contained. in another portion otsaid compressed refrigerant gas for concentrating said two-phaseoily-watery mixture by distilling a avorful and aromatic mixture of saidhigh and low boiling constituents from the resulting two-phaseoilywatery mixture at a temperature approximating 100 F. and an absolutepressure of less than 11/2" of mercury by causing a thin film thereof totravel along a heat exchange surface, using a portion of said coolliquefied refrigerant to condense a minor subtraction of theconstituents volatilized from said two-phase oily-watery mixture tocondense a minor subtraction containing a watery phase and an oilyphase, a major portion of said rninor subtraction being the watery phaseand a minor proportion of said minor subtraction being the oily phase,and combining the lat-ter subtraction with a portion of saidconcentrated juice.

8. A continuous process for producing a flavor enhanced juice selectedfrom the group consisting of apple and prune by concentrating :a heatsensitive juice and separating and recovering therefrom a specificfraction l1 of volatile constituents whose boiling points are above andbelow that of water, comprising utilizing the heat c-ontained in acompressed refrigerant gas for boiling the juice at relatively -lowtemperatures of from 70- 14D F. under vacuum to partially concentratesaid juice by separating it into a major concentrated juice portion anda minor volatile portion which contains volatile avor-eproducingIconstituents, water and non-condensable gaseous constituents,liquefying and causing the refrigerant to cool to a temperaturesubstanti-ally below the temperature of said minor volatile portion,introducing said liquefied refrigerant and said Iminor volatile portionto a heat exchanger to :condense a major portion of said minor volatileportion 4as a first two-phase oilywatery mixture and to evaporate theliquid refrigerant, discarding uncondensed volatile constituents andsaid noncondensable gases as a minor proportion of said minor volatileportion, recompressing said evaporated refrigerant gas, utilizing `theheat contained in said compressed refrigerant gas for concentrating saidtwo-phase oily-watery mixture by distilling a flavorful and aromaticmixture of said high and low boiling constituents from the resultingtwo-phase oily-watery mixture at a temperature approxi-mately 100 F. andan absolute pressure less than 11/2" of mercury by causing a thin lm ofsaid two-phase oily-watery mixture to travel along a heat exchangesurface, and. utilizing a portion of said cool liqueed refrigerant ytocondense a minor subtraction of the volatiles distilled from saidtwo-phase oily-watery mixture so as to contain a watery phase as a majorportion of said minor subfraction and an oily phase as la minor portionof said minor subtraction and combining said -rninor subfraction with aportion of said concentrated juice.

References Cited by the Examiner UNITED STATES PATENTS 1/1964 Byer etal. 99-205 1/1964 Byer et al. 99-205

1. PROCESS OF SEPARATING AND RECOVERING FROM A JUICE SELECTED FROM THEGROUP CONSISTING OF APPLE AND PRUNE A SPECIFIC FRACTION OF VOLATILECONSTITUENTS WHOSE BOILING POINTS ARE BELOW AND ABOVE THAT OF WATER,COMPRISING SEPARATING THE JUICE INTO A MAJOR CONCENTRATED JUICE PORTIONAND A MINOR VOLATILE PORTION WHICH CONTAINS SAID VOLATILEFLAVOR-PRODUCING CONSTITUENTS AND NON-CONDENSABLE GASEOUS CONSTITUENTSBY SUBJECTING THE JUICE TO A HIGH VACUUM CONCENTRATION OPERATION AT ATEMPERATURE LESS THAN 140*F., CONDENSING A MAJOR PROPORTION OF THEVOLATILE FLAVOR-PRODUCING CONSTITUTENTS AS A FIRST TWO-PHASE OILY-WATERYMIXTURE AND EVACUATING UNCONDENSED VOLATILE CONSTITUENTS ANDNON-CONDENSABLE GASES AS A MINOR PROPORTION OF THE VOLATILE PORTION,DISCARDING SAID MINOR PROPORTION OF THE VOLATILE PORTION, AND THEREAFTERDISTILLING A FLAVORFUL AND AROMATIC MIXTURE OF SAID HIGH AND LOW BOILINGCONSTITUENTS FROM THE RESULTING TWO-PHASE OILYWATERY MIXTURE AT ATEMPERATURE OF 50*-100*F. AND AN ABSOLUTE PRESSURE OF LESS THAN 1 1/2"OF MERCURY BY CAUSING A THIN FILM OF SAID TWO-PHASE OILY-WATERY MIXTURETO TRAVEL ALONG A HEAT EXCHANGE SURFACE AND CONDENSING A MINORSUBFRACTION OF SAID MIXTURE, A MAJOR PORTION OF SAID MINOR SUBFRACTIONBEING A WATERY-PHASE AND A MINOR PORTION OF SAID SUBFRACTION BEING ANOILY-PHASE.